A former senior diplomat has acknowledged he is one of two ex-diplomats singled out in a report on leaks from the Ministry of Foreign Affairs and Trade.

New Zealand's former top trade negotiator Nigel Fyfe – now a senior official in the Ministry of Justice – was alluded to, but not named, in the report by former Commerce Commission head Paula Rebstock on her $500,000, 18-month inquiry into the leaks.

Fyfe and Derek Leask, a former High Commissioner to the United Kingdom now retired, have been fighting behind the scenes for more than a year to clear their names. The inquiry focused on email exchanges between them.

The Rebstock inquiry was set up after three confidential Cabinet documents were leaked to Labour MP Phil Goff.

The inquiry's aim was to establish who leaked the documents - and ultimately concluded that a temporary clerical worker at the State Services Commission, previously a Labour staffer, was the most likely culprit.

The leaks threw open the doors on proposed changes designed to cut a swathe through MFAT's ranks and would have hacked into pay and conditions, as well as outsourced some consular services, and seen the loss of hundreds of jobs.

Fyfe this afternoon confirmed he is one of the two former diplomats singled out in the report. The report refers to persons X, Y and Z.

In a statement issued through his lawyer Hugh Rennie, Fyfe - currently deputy secretary at the Ministry of Justice - said he was the person referred to as Y in the Rebstock report.

"Despite the report's use of that description it contains extensive information which identifies him," the statement from Rennie said.

"The plain intention of the State Services Commission is to identify him by indirect means. He is disclosing his name to avoid any unfair effect on past and present MFAT staff."

In a statement, Person Z said he had no choice but to comment, given remarks in the media.

"I simply do not accept the validity of the findings against me and some of my former colleagues. And neither will many others with long and deep involvement in MFAT and elsewhere in the public service."

Rennie said Fyfe had been asked by the Rebstock inquiry to be interviewed and to provide information about his role in the 2012 restructuring of MFAT.

Rennie said Fyfe did not leak or release any information to media or politicians and had co-operated fully with the Rebstock inquiry.

But the inquiry appeared to have predetermined outcomes, one of which was to "attack Mr Fyfe in particular".

"Mr Fyfe acted within the State Sector Code of Conduct and in accordance with his knowledge of public sector practices gained over many years. "

Rebstock said in her report that there was a strong suspicion - but no definitive evidence - that the leak was made by the temporary staff member - a clerical assistant within the State Services Commission, who was a former Labour Party staffer.

She does not name the temporary staffer, whose name is suppressed by the High Court.

The report also singled out a group of senior public servants at MFAT for criticism. Their conduct "fell below the standards expected of people in their position", it says.

The inquiry found no evidence either Person Y or Z leaked documents or sensitive material, but accessed their private emails and phone logs to claim "they created a perception in the department that it was acceptable for opposition to the proposed changes to be aired outside the department and used for political purposes".

State Services Commissioner Iain Rennie and Foreign Minister Murray McCully have since attacked the actions of persons Y and Z.

NO DEFINITIVE EVIDENCE

McCully labelled their conduct "unprofessional and disreputable" and designed to undermine proposed changes within the ministry.

Most of MFAT was up in arms and the proposals prompted an extraordinary gathering of more than 40 heads of mission who flew in from around the world to voice their alarm at the potential damage to New Zealand's diplomatic outreach overseas.

Many of the proposals were ditched after morale at MFAT plummeted and senior diplomats starting quitting the organisation.

In his statement, Person Z said his approach throughout the change process had been to get significant improvements to the outcome.

"I worked with colleagues to achieve this. The MFAT secretary acknowledged that the robust debate had helped to achieve this. And I wasn't the only person concerned by the change proposals - the prime minister and foreign minister also expressed concerns."

The report published emails between Y and Z to criticise their actions.

In his statement, Z said the emails were private communications between colleagues, "like water cooler conversations in an office, except we were in different parts of the world".

"This was an investigation that misunderstood the MFAT change process. Challenging the senior management is not undermining it - it is part of the process. Our concerns were underpinned by loyalty to MFAT and NZ's interests."

He was surprised and disappointed by the decision of the State Services Commissioner to publish the section on person Y and Z.

"My counsel had given him what we saw as ample evidence that important corrections were required to the final report given to him by the investigation. My counsel has lodged a formal complaint with the Privacy Commission.

"We pointed out, for example, that finding D implied that I had not maintained political neutrality. I argued that this was not accurate and that the finding should be deleted. As someone who was a serious public servant for over 40 years I find the publication of this finding insulting and I believe it is defamatory."

He had also provided to the investigation and the SSC his disagreement with the investigations claims that he and others had disregarded instructions from the MFAT CEO.

He had found it difficult to deal over 18 months with a series of four different accusations.

"Accusations were made, they were strongly disputed by [myself] and counsel, and then they would apparently be shelved only to be replaced by others."

"I saw the change proposals put forward in February 2012 as seriously flawed. My concern about the proposals was widely shared including by 49 Heads of Mission, Ministers and Many current and former senior MFAT staff.

"I told the investigation time and again that I was fully entitled to work openly with colleagues and without ever having my views become public to ensure that relevant analysis and arguments and points of view were bought to bear during the consultation period."

In her report, Rebstock accused "two tier 3 managers" within MFAT of developing strategies to oppose the change proposals and to disrupt or stop the change process.

The inquiry was disrupted by legal challenges after person X, the former Labour Party staffer, fought to have the part of the report dealing with their role in any leak through the High Court and Appeal Court.

DISAPPOINTED

Iain Rennie said, releasing the report, that he was "extremely saddened and disappointed".

"If the leak came from within the SSC then the individual who chose to behave like this has badly let down colleagues."

Rebstock had also found some MFAT staff leaked a variety of in-confidence material either directly or indirectly to the Goff and to the media.

Goff said the Cabinet papers came to his office but he did not know who sent them.

"I have no idea of their identity, whether male or female or where they work."

He was not interviewed by the Rebstock inquiry.

Rennie said he had considered whether it was in the public interest to release the names of X, Y and Z, but did not believe it was.

He did not want to indulge in a witch-hunt over matters that were very historical.

The report had already taken a lot of time and cost significant expenditure of public money.

"I made the judgment that if I moved to disclose the names ... it was likely there would be further litigation leading to further delay and expense of public money, so overall I believe the benefits of disclosing the identities of the individuals here are well exceeded by the costs of doing so on a number of fronts."

Asked if he had taken any disciplinary action against the individuals, he said that would be up to the chief executive of departments who might consult him.

He had received the final report, dated November 27, only recently, suggesting it was too soon to have taken any disciplinary action that might follow.

"Issues about a disciplinary action are hypothetical," Rennie said.

However, he would not be leaving the report "in the ether", he said.

Goff said the report was an attack on MFAT staffers who objected to unilateral actions being taken on their job security and positions and who felt it would undermine the effectiveness of MFAT.

"Did they think they were going to do that without scrutiny?"

The inquiry should have focused on the "botched" restructuring at MFAT, he said.

McCully said the report suggested some officials had been placed under pressure by Goff to release information that they had not been entitled to release.

McCully said the report, which he had not seen until yesterday, had been a distraction.

"The report finds that a very small number of individuals in the ministry engaged in unprofessional and disreputable conduct designed to undermine proposed changes within the ministry," McCully said.

"It also makes clear that the worst, and possibly only serious offenders, are no longer with the ministry."

Meanwhile, the Public Service Association National Secretary Brenda Pilott said not only was a lot of time and money spent coming up with nothing in terms of evidence in the inquiry but ''many people were put through an unnecessarily interrogation-like process which created a climate of fear''.